扩散加权成像在脑后部可逆性脑病综合征早期诊断中的应用

目的探讨扩散加权成像(DWI)对脑后部可逆性脑病综合征(PRES)的早期诊断及鉴别诊断的应用价值。方法回顾性分析12例PRES患者的临床及影像学资料,12例患者均行CT、MRI平扫及DWI检查,其中2例患者行MR增强检查。结果 MR及CT显示双侧顶枕叶9例、基底节区3例、额颞叶2例、小脑2例、丘脑1例、胼胝体1例及脑干1例多发斑片状异常信号或低密度影,主要位于双侧顶枕叶皮质及皮质下白质内。MR表现为稍长T1、稍长T2信号,FLAIR呈高信号,2例增强后病变未见强化,12例患者高b值DWI均呈等信号,相应ADC图呈高信号。所有患者接受治疗后复查MRI,病灶逐渐缩小、消失,临床症状好转。结论 DWI能明确PRES早期病变为血管源性水肿,DWI并结合常规MR对PRES的早期诊断、鉴别诊断及患者治疗后影像学评价有极高的价值。

Application of diffusion-weighted imaging in the early diagnosis of posterior reversible encephalopathy syndrome

Objective To investigate the application value of diffusion-weighted imaging(DWI)in the early diagnosis and differential diagnosis of posterior reversible encephalopathy syndrome(PRES).Methods The clinical and imaging data of 12 patients with PRES were retrospectively analyzed.12 patients underwent CT,MRI and DWI.2 cases of them underwent MR enhancement.Results MR and CT showed there were 9 cases of multiple patchy abnormal signals or low density shadows in bilateral occipital lobe,3 cases in basal ganglia,2 cases in frontal lobe,2 cases in cerebellum,1 case in thalamus,1 case in corpus callosum and 1 case in brainstem,mainly located in the bilateral occipital cortex and subcortical white matter.MR showed a slightly longer T1,slightly longer T2 signal,and FLAIR showed a high signal.2 cases of lesions were not enhanced after enhancement.12 patients with high b value DWI showed equal signals,and the corresponding ADC map showed a high signal.All patients underwent MRI after treatment,showing the lesions gradually narrowed and disappeared,and the clinical symptoms were improved.Conclusion DWI can confirm the early stage of PRES as angiogenic edema.DWI combined with conventional MR is of great value in the early diagnosis,differential diagnosis and post-treatment imaging evaluation of PRES.